My raid5 array has gotten a bit big, it's containing total 10 drives right now (I started out with 3 drives). So I am going to convert it to raid6 before it gets any bigger. I am doing a test-run on a virtual machine with virtual drives to see that everything works flawlessly. When I tried to convert the array to raid6 I got a error message about a missing backup-file mdadm --grow /dev/md0 --raid-devices=5 --level=6 mdadm level of /dev/md0 changed to raid6 mdadm: /dev/md0: Cannot grow - need backup-file mdadm: aborting level change I added the backup file and was able to convert the array successfully after that. My question is, how big is this backup file going to be? My real raid array consists of 2tb drives, will the backup file be as big as one drive in the array, or will it just be few megabytes or gigabytes? I'm asking because I'm wondering if I need to buy an extra hdd for the backup file or if the backup file can just be on my OS hdd that has around 100gb free. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
